Causal/Predictive Imperfect Channel State Information in Block-Fading Channels

TL;DR

This paper analyzes the impact of imperfect causal and predictive channel state information on the diversity-multiplexing and rate-diversity tradeoffs in MIMO block-fading channels, providing new insights for system design.

Contribution

It introduces a comprehensive model for imperfect causal and predictive CSIT and derives the optimal DMT and RDT under long-term power constraints.

Findings

Imperfect CSIT affects outage diversity gains.

Causal and predictive CSIT improve system performance.

New bounds on DMT and RDT with mismatched CSIT.

Abstract

We consider a multi-input multi-output (MIMO) block-fading channel with a general model for channel state information at the transmitter (CSIT). The model covers systems with causal CSIT, where only CSIT of past fading blocks is available, and predictive CSIT, where CSIT of some future fading blocks is available. The optimal diversity-multiplexing tradeoff (DMT) and rate-diversity tradeoff (RDT) of the channel are studied under long-term power constraints. The impact of imperfect (mismatched) CSIT on the optimal DMT and RDT is also investigated. Our results show the outage diversity gain obtained by providing imperfect causal/predictive CSIT, leading to new insights into system design and analysis.